• Title/Summary/Keyword: mathematical representation

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ALL GENERALIZED PETERSEN GRAPHS ARE UNIT-DISTANCE GRAPHS

  • Zitnik, Arjana;Horvat, Boris;Pisanski, Tomaz
    • Journal of the Korean Mathematical Society
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    • v.49 no.3
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    • pp.475-491
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    • 2012
  • In 1950 a class of generalized Petersen graphs was introduced by Coxeter and around 1970 popularized by Frucht, Graver and Watkins. The family of $I$-graphs mentioned in 1988 by Bouwer et al. represents a slight further albeit important generalization of the renowned Petersen graph. We show that each $I$-graph $I(n,j,k)$ admits a unit-distance representation in the Euclidean plane. This implies that each generalized Petersen graph admits a unit-distance representation in the Euclidean plane. In particular, we show that every $I$-graph $I(n,j,k)$ has an isomorphic $I$-graph that admits a unit-distance representation in the Euclidean plane with a $n$-fold rotational symmetry, with the exception of the families $I(n,j,j)$ and $I(12m,m,5m)$, $m{\geq}1$. We also provide unit-distance representations for these graphs.

Representation Systems of Building Blocks in Logo-based Microworld

  • Lee, Ji-Yoon;Cho, Han-Hyuk;Song, Min-Ho;Kim, Hwa-Kyung
    • Research in Mathematical Education
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    • v.15 no.1
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    • pp.1-14
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    • 2011
  • Logo has influenced many researchers and learners for the past decades as a 20 turtle geometry environment in the perspective of constructionism. Logo uses the metaphor of 'playing turtle' that is intrinsic, local and procedural. We, then, design an environment in which the metaphor of 'playing turtle' is applied to construct 3D objects, and we figure out ways to represent 3D objects in terms action symbols and 3D building blocks. For this purpose, design three kinds of representation systems, and asked students make various 3D artifacts using various representation systems. We briefly introduce the results of our investigation into students' cognitive burden when they use those representation systems, and discuss the future application measures and the design principles of Logo-based 3D microworld.

Mathematical Creativity and Mathematics Curriculum: Focusing on Patterns and Functions (창의성 관점에서 본 제 7차 초등 수학과 교육과정: 규칙성과 함수를 중심으로)

  • 서경혜;유솔아;정진영
    • Education of Primary School Mathematics
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    • v.7 no.1
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    • pp.15-29
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    • 2003
  • The present study examined the 7th national elementary school mathematics curriculum from a perspective of mathematical creativity. The study investigated to what extent the activities in the Pattern and Function lessons in the national elementary school mathematics textbooks promoted the development of mathematical creativity. The results indicated that the current elementary school mathematics curriculum was limited in many ways to promote the development of mathematical creativity. Regarding the activities in Pattern lessons, for example, most activities presented closed tasks involving finding and extending patterns. The lesson provided little opportunities to explore the relationships among various patterns, apply patterns to different situations, or create ones own patterns. In regard to the Function lessons, the majority of activities were about computing the rate. This showed that the function was taught from an operational perspective, not a relational perspective. It was unlikely that students would develop the basic understanding of function through the activities involving the computing the rate. Further, the lessons had students use exclusively the numbers in representing the function. Students were provided little opportunities to use various representation methods involving pictures or graphs, explore the strengths and limitations of various representation methods, or to choose more effective representation methods in particular contexts. In conclusion, the lesson activities in the current elementary school mathematics textbooks were unlikely to promote the development of mathematical creativity.

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INTEGRAL FORMULAS FOR EULER'S CONSTANT

  • JUNESANG CHOI;TAE YOUNG SEO
    • Communications of the Korean Mathematical Society
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    • v.13 no.3
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    • pp.683-689
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    • 1998
  • There have been developed many integral representations for Euler's constant some of which are recorded here. We are aiming at showing a (presumably) new integral form of Euler's constant and disproving another integral representation for this constant which were recently proposed by Jean Angelsio, Garches, France, in American Mathematical Monthly. By modifying the Angelsio's incorrectly proposed integral form of Euler's constant, we also provide an integral representation for Euler's constant.

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ON A q-FOCK SPACE AND ITS UNITARY DECOMPOSITION

  • Ji, Un-Cig;Kim, Young-Yi
    • Bulletin of the Korean Mathematical Society
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    • v.43 no.1
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    • pp.53-62
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    • 2006
  • A Fock representation of q-commutation relation is studied by constructing a q-Fock space as the space of the representation, the q-creation and q-annihilation operators (-1 < q < 1). In the case of 0 < q < 1, the q-Fock space is interpolated between the Boson Fock space and the full Fock space. Also, a unitary decomposition of the q-Fock space $(q\;{\neq}\;0)$ is studied.

An Analysis of Mathematical Communication in Elementary Mathematics (초등수학의 수학적 의사소통에 관한 분석)

  • Ahn, Byoung-Gon
    • Journal of Elementary Mathematics Education in Korea
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    • v.15 no.1
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    • pp.161-178
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    • 2011
  • For the students who live in the knowledge-information oriented society, thinking rationally and training mathematical communication ability are necessary. I represented three ways of teaching-learning related to mathematical communication in revised 2006 curriculum of elementary mathematics. In this study, based on three matters from devised curriculum, I have done survey-analysis of mathematical representation and characteristics of contents of major theses about mathematical communication published after 2007 curriculum revision, for further mathematical communication teaching.

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Analysis of Effect of Learning to Solve Word Problems through a Structure-Representation Instruction. (문장제 해결에서 구조-표현을 강조한 학습의 교수학적 효과 분석)

  • 이종희;김부미
    • School Mathematics
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    • v.5 no.3
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    • pp.361-384
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    • 2003
  • The purpose of this study was to investigate students' problem solving process based on the model of IDEAL if they learn to solve word problems of simultaneous linear equations through structure-representation instruction. The problem solving model of IDEAL is followed by stages; identifying problems(I), defining problems(D), exploring alternative approaches(E), acting on a plan(A). 160 second-grade students of middle schools participated in a study was classified into those of (a) a control group receiving no explicit instruction of structure-representation in word problem solving, and (b) a group receiving structure-representation instruction followed by IDEAL. As a result of this study, a structure-representation instruction improved word-problem solving performance and the students taught by the structure-representation approach discriminate more sharply equivalent problem, isomorphic problem and similar problem than the students of a control group. Also, students of the group instructed by structure-representation approach have less errors in understanding contexts and using data, in transferring mathematical symbol from internal learning relation of word problem and in setting up an equation than the students of a control group. Especially, this study shows that the model of direct transformation and the model of structure-schema in students' problem solving process of I and D stages.

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